distance d       orbital radius     central mass          acceleration
    (Mpc)                r                M                     m/s^2
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                           3                   7                     -4
     5              25 x 10  AU        2.8 x 10   solar      2.7 x 10   

                          15                   37                     
                  3.7 x 10   m         5.6 x 10   kg


                           3                   7                     -4 
     7              35 x 10  AU        3.9 x 10  solar       1.9 x 10   

                          15                   37                     
                  5.2 x 10   m         7.9 x 10   kg


                           3                   7                     -4
    10              50 x 10  AU        5.6 x 10  solar       1.3 x 10   

                          15                   37                     
                  7.5 x 10   m        11.2 x 10   kg



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